Non main CPU/OS based operational environment

ABSTRACT

A computing system is described that includes a main system bus that remains active while said computing system operates within a non main CPU/OS based operational state. The computing system also includes a controller that operates functional tasks while the computing system is within the non main CPU/OS based operational state. The computing system also includes an I/O unit coupled to the main system bus that remains active while the computing system operates within the non main CPU/OS based operational state.

PRIORITY

This application is a continuation of and claims the priority date ofU.S. application Ser. No. 11/435,264, filed May 15, 2006 now U.S. Pat.No. 7,428,650 which is a divisional of U.S. application Ser. No.10/367,566, filed Feb. 14, 2003, now Issued U.S. Pat. No. 7,080,271.

FIELD OF INVENTION

The field of invention relates generally to computing; and, morespecifically, to a non main CPU/OS based operational environment.

BACKGROUND

A. Computing Systems

FIG. 1 shows an embodiment of a computing system 100. The computingsystem includes a Central Processing Unit (CPU) 101, a cache 102, memoryand I/O control 103 and a system memory 104. Software instructionsperformed by the computing system (and its corresponding data) arestored in the system memory 104 and cache 102 (where frequently usedinstructions and data are stored in cache 102). The softwareinstructions (together with corresponding data) are executed by the CPU101. The memory controller portion of the memory and I/O control 103 isresponsible for managing access to the system memory 104 (which may beused by functional elements other than the CPU 101 such as the graphicscontroller 105 and various I/O units).

The graphics controller 105 and display 106 provide the computergenerated images observed by the user of the computing system 100. TheI/O controller of the memory and I/O control function 103 is responsiblefor managing access to the system memory 104 (and/or CPU 101) forvarious I/O units 108 ₁ through 108 _(N) and 109, 111, 113 and 115. I/Ounits are typically viewed as functional units that send/receiveinformation to/from the computing system (e.g., a networking adapter, aMODEM, a wireless interface, a keyboard, a mouse, etc.) and/orfunctional units used for storing the computing system's informationwithin the computing system 100 (e.g., a hard disk drive unit).

Various I/O units are frequently found within a computing system; and,moreover, various types of interfaces for communication between an I/Ounit and the I/O control function are frequently found within acomputing system. Often, these interfaces are defined by an industrystandard. The exemplary computing system architecture of FIG. 1 shows asystem bus interface 107 into which different I/O units 108 ₁ through108 _(N) may be plugged; and, different interfaces 110, 112, 114 and116. Each of the different interfaces 110, 112, 114 and 116 is drawn inFIG. 1 as having its own corresponding I/O unit 109, 111, 113 and 115.

Note that a different number of interfaces may be entertained fromcomputer system to computer system; and, different interface types(e.g., in terms of the maximum number of I/O units per interface,interfacing technique, etc.) may be entertained from computer system tocomputer system. As just one possible implementation, using thecomputing system of FIG. 1 as a template: 1) system bus 107 is a PCIbus; 2) interface 110 is a serial port; 3) interface 112 is a USBinterface; 4) interface 114 is a serial interface; and 5) interface 116is an IDE interface (or other storage device interface)

B. Computing System State Diagram

FIG. 2 shows a prior art state diagram for a computing system. Anembodiment of the operating states observed in FIG. 2 may be found inthe Advanced Configuration and Power Interface (ACPI) Specification,Revision 2.0a dated Mar. 31, 2002 (and published by Compaq ComputerCorporation, Intel Corporation, Microsoft Corporation, PhoenixTechnologies Ltd., and Toshiba Corporation). Although the ACPIspecification is recognized as describing a large number of existingcomputing systems, it should be recognized that large numbers ofcomputing systems that do not conform to the ACPI specification canstill conform to the operating state configuration observed in FIG. 2.As such, the description of FIG. 1 corresponds to a more genericdescription that the ACPI specification conforms to.

According to the depiction of FIG. 2 a first state 201, referred to asthe “normal on” state 201, is the normal operating state of the computer(i.e., the state of the computer when it is actively powered and isbeing (or is ready to be) used by a user). Within the ACPIspecification, the “normal on” state 201 is referred to as the “GO”state. A second state 202 refers to any of one or more states where thecomputing system is recognized as being “off”. The ACPI specificationrecognizes two such states: a hardware based off state (e.g., wherepower has been removed from the entire system) and a software based offstate (where power is provided to the system but the BIOS and operatingsystem (OS) have to be reloaded from scratch without reference to thestored context of a previously operating environment). The ACPIspecification refers to the hardware based off state as the “G3” stateand the software based off state as the “G2” state.

A third state 203 refers to any of one or more states where thecomputing system is recognized as “sleep”. For sleep states, theoperating environment of a system within the “normal on” state 201(e.g., the state and data of various software routines) are saved priorto the CPU of the computer being entered into a lower power consumptionstate. The sleep state(s) 203 are aimed at saving power consumed by theCPU over a lull period in the continuous use of the computing system.That is, for example, if a user is using a computing system in thenormal on state 201 (e.g., typing a document) and then becomesdistracted so as to temporarily refrain from such use (e.g., to answer atelephone call)—the computing system can automatically transition fromthe normal on state 201 to a sleep state 202 to reduce system powerconsumption.

Here, the software operating environment of the computing system (e.g.,including the document being written), which is also referred to as“context” or “the context”, is saved beforehand. As a consequence, whenthe user returns to use the computing system after the distraction iscomplete, the computing system can automatically present the user withthe environment that existed when the distraction arose (by recallingthe saved context) as part of the transition back to the normal state201 from the sleep state 203. The ACPI specification recognizes acollection of different sleep states (notably the “S1” “S2”, “S3” and“S4” states) each having its own respective balance between powersavings and delay when returning to the “normal on” state 201 (here, theS1, S2 and S3 states are recognized as being various flavors of“standby” and the S4 state is a “hibernate” state).

A problem with prior art sleep states, however, is that the CPU isunable to perform any useful work. As such, although power savings arerecognized, any tasks that may have been useful to perform during thetime period over which the computing system was sleep are impossible toimplement.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be best understood by referring to the followingdescription and accompanying drawings that are used to illustrateembodiments of the invention. In the drawings:

FIG. 1 shows an embodiment of a computing system;

FIG. 2 shows a prior art state diagram for a computing system;

FIG. 3 shows an improved state diagram for a computing system havinguseful low power states;

FIG. 4 a through FIG. 4 c demonstrate an embodiment of the relationshipbetween active and inactive computing system hardware components for,respectively, a “normal on” state (FIG. 4 a), a “main CPU/OS based lowpower” state (FIG. 4 b), and a “non main CPU/OS based lower power” state(FIG. 4 c);

FIG. 5 shows an embodiment of the distribution of various functionalroles for a complete telephone system across, respectively, a “normalon” state, a “main CPU/OS based low power” state, and a “non main CPU/OSbased lower power” state;

FIGS. 6 a and 6 b demonstrate exemplary method flows for transitioningfrom a “normal on” state to a “main CPU/OS based low power” state (FIG.6 a); and, for transitioning from a “main CPU/OS based low power” stateto a “normal on” state (FIG. 6 b);

FIG. 7 shows an embodiment of state transition logic that may be used toassist/control a computing system's transitions between: 1) a “normalon” state and one or more sleep states; and, 2) a “main CPU/OS based lowpower” state and a “non main CPU/OS based lower power” state;

FIGS. 8 a and 8 b demonstrate exemplary method flows for transitioningfrom a “main CPU/OS based low power” state to a “non main CPU/OS basedlower power” state (FIG. 8 a); and, for transitioning from a “non mainCPU/OS based lower power” state to a “main CPU/OS based low power” state(FIG. 8 b);

FIG. 9 a shows a more detailed embodiment of a computing system having alow power but operable non main CPU/OS based subsystem;

FIG. 9 b shows an embodiment of a pair of mobile computing systems thateach provide a “closed lid” user interface;

FIG. 10 shows an embodiment of a software architecture for a “mainCPU/OS based low power” state, an embodiment of a software architecturefor a “non main CPU/OS based lower power” state; and, possiblerelationships between the pair of states;

FIG. 11 illustrates an example of a number of state transitions thatreact to the use of a computing system over time.

DESCRIPTION

State Diagram and Computing System Having Operational Low Power States

In order for a computing system to perform useful tasks from within alow power consumption state, special states need to be designed into thesystem. In particular, these special states should be configured to havea sufficient amount of functional prowess so that one or more usefultasks can be executed; while, at the same time, consume power at a ratethat is lower than those associated with the “normal on” state. Here,FIGS. 3 and 4 a through 4 c illustrate an embodiment of a computingsystem having two such special states.

FIG. 3 presents a state diagram. FIGS. 4 a through 4 c show an exemplarydepiction of the various components of an exemplary computing systemthat are not forced into a low power state or are forced into a lowpower state within each state from which useful tasks may be performed(where a shaded region indicates that a component has been forced toremain within an inactive low power state and a non shaded regionindicates a component has not been forced to remain within an inactivelow power state). It is important to note that, as explained in moredetail below, both the computing system and the particular combinationof inactive low power state forced components and non inactive low powerstate forced components that are observed in FIGS. 4 a through 4 c areexemplary and may vary from embodiment to embodiment.

According to the state diagram scheme observed in FIG. 3, a computingsystem has three primary states were useful tasks can be performed: 1) ahigh power, “normal on” state 301; 2) a “main CPU/OS based low power”state 304; and, 3) a “non main CPU/OS based lower power” state 305.FIGS. 4 a through 4 c show an exemplary embodiment of a single computingsystem for each of the above described states. A brief overview of eachof these states is provided immediately below followed by a morethorough discussion of the “main CPU/OS low power” state 304 and the“non main CPU/OS lower power” state 305.

FIG. 4 a shows an embodiment of a “normal on” state 301 computingsystem. Note that none of the computing system's various components havebeen forcibly entered into an inactive low power state because none ofthe components are shaded. In various embodiments, at least some of thecomputing system's components are given the authority to regulate theirown power consumption (e.g., from a lowest power consumption state to ahighest power consumption state) in light of detected usage. Here, bynot forcing a component into an inactive low power state, componentsthat have the ability to regulate their own power consumption are freeto do so within the “normal on” state 301.

By contrast, FIG. 4 b shows an embodiment of the same computing systemafter it has been placed into the “main CPU/OS based low power” state304. Here, certain components (indicating by shading) have been forcedinto an inactive low power state. Consistent with this perspective,those components that have the authority to regulate their own powerconsumption and who are to be forced into an inactive low power stateare stripped of their power regulation authority and are forced intotheir lowest power consumption state. Here, note that the term“inactive” means the component has ceased its primary function(s) sothat power may be conserved. Note that the main CPU has not beeninactivated and can therefore continue to execute software programs.

FIG. 4 c shows an embodiment of the same computing system after it hasbeen placed into the “non main CPU/OS based lower power” state 305.Here, note that additional components (in particular, the CPU) have beenplaced into an inactive low power state as indicated by additionalshading as compared to FIG. 4 b.

A more thorough discussion of the “main CPU/OS low power” state 304 andthe “non main CPU/OS lower power” state 305 is provided immediatelybelow.

Referring to FIGS. 3 and 4 b, the “main CPU/OS based low power” state304 corresponds to a state in which the main CPU 401 is powered on andcan execute software; yet, the overall power consumption is reduced ascompared to the “normal on” state 301. Because the main CPU can executesoftware based upon the main Operating System (OS), state 304 isreferred to as “main CPU/OS based”. Power may be reduced by one or moreof the techniques described immediately below.

1) Computing system components other than the CPU that have theintelligence/ability to dynamically regulate their own power consumptionare stripped of their authority to dynamically regulate their own powerconsumption; and, instead, are forced into their lowest power state. Forexample, in the case of an ACPI compliant system, various componentswithin a computing system (including the display, graphics controller,various I/O devices (such as the hard disk drive), etc.) are given theauthority to regulate their own power consumption (e.g., based uponobserved usage through their device driver) according to a plurality ofstates D0 through D3; where, the D0 state is the highest power operatingstate and the D3 state is the lowest power non-operating state (D1 andD2 also being non-operating states with increasingly lower power). In anembodiment, the “main CPU/OS based low power” state 304 deliberatelyconfigures certain components to permanently remain within the D3 stateso long as the system resides within the “main CPU/OS based low power”state 304. Non ACPI systems may be similarly configured. In FIG. 4 b,components that have been forced into their lowest power state areshaded; hence, in the example of FIG. 4 b, the graphics controller 405,the display 406 and I/O units 408 ₂ through 408 _(N) are forced intotheir lowest power state. In alternate embodiments, it may be possibleto design certain components so that their power supply voltage isreduced or removed while the system is within the “non main CPU/OS basedlow power” state 304.

2) If the CPU is capable of dynamically adjusting its power consumptionamongst a plurality of different power consumption states (e.g., bydynamically changing its internal voltage levels and/or clockingfrequencies), the CPU is forced to operate within the lowest power state(or amongst the lowest power states). For example, Intel SpeedStep™Technology based CPUs may have different “P_(n)” states: P₀ through P₄;where, P₀ is the highest power state and P₄ is the lowest power state. ASpeedStep™ Technology based CPU reduces power by reducing both itsvoltage and frequency to get a dramatic decrease in power with amoderate decrease in performance. In an embodiment that employs aSpeedstep™ Technology based CPU, while the computing system is withinthe “non main CPU/OS low power” state 304, the CPU is forced to operatein the P₄ state (although some application policies may allow forspecial exceptions for entry into the next lowest power state P₃). Notethat other CPUs may exist that reduce power by reducing either or bothvoltage and frequency—yet—are not SpeedStep™ Technology based CPUs. Assuch, the technique presently being described may be implemented withboth SpeedStep™ Technology based CPUs and non SpeedStep™ based CPUs. Infurther embodiments, to the extent the internal clocking frequency canbe adjusted while within a lowest power state, the clock frequency isset to the lowest clock frequency that the processor can properlyoperate at.

3) Defining application software programs that are not to be used withinthe “non main CPU/OS low power” state 304 and suspending their useduring this state. Any software task or application that is deemed notuseful or needed for the implementation of “main CPU/OS based” low powerstate 304 and the “non main CPU/OS based” lower power state 305 could besuspended to achieve very low system power. Examples may include ascreen saver, a word processing application, a presentation/graphicsapplication, and/or a spreadsheet application program. Moreover, anybatch computing jobs could be suspended during operation in states 504and 505.

4) In a computing system having multiple main CPUs (i.e., CPU 101 ofFIG. 1 actually includes a plurality of CPUs), the number of activelyworking CPUs is reduced (e.g., in a system having N main CPUs during the“normal on” state 301), only one such main CPU is active during the“main CPU/OS low power” state 304.

Referring to FIGS. 3 and 4 c, the “non main CPU/OS based lower power”state 305 corresponds to a state in which the main CPU 401 is powereddown so that it cannot execute software based upon the computingsystem's main OS. Note that in the example of FIG. 4 c the cache 402 thesystem memory 404, and at least the memory controller portion of thememory I/O control unit 403 are also be forcibly entered into aninactive, low power state (because they largely support the main CPU's401 efforts to execute software). Because the main CPU 401 is inactive,state 305 is “non main CPU/OS based”. Moreover, at least because the CPU401 has been made inactive, state 305 is “lower power” as compared tostates 301 and 304. Hence, state 305 may be referred to as a “non mainCPU/OS based lower power” state. It is important to note however, thatthe precise combination of components that are forced inactive duringstate 305 may vary from embodiment (e.g., as one example, a system maybe designed that keeps system memory 404 active during the “non mainCPU/OS based lower power” state 305 so that the system memory 404 can beused within that state 305.

Exemplary Implementation: Complete Cordless Telephone System

The incorporation of states 301, 304 and 305 (e.g., as per the computingsystem powering profile observed in FIGS. 4 a through 4 c) allow acomputing system to be specially tailored to produce certain tasks whilein various stages of reduced power consumption—and, as a consequence,better efficiency should result. An example helps demonstrate thepotential of this approach. FIG. 5 shows an exemplary “complete”—yetenergy efficient—cordless telephone system that can be implemented witha computing system as outlined in FIGS. 3 and 4 a through 4 c. Here acomplete cordless telephone system is a system that: 1) provides a basiccordless telephone function (i.e., a Plain Old Telephone Service (POTS)interface and a wireless link between a cordless telephone and the POTSinterface); 2) an answering machine that records a caller's messageshould the cordless phone remain unanswered in response to the caller'scall; and, 3) a Net Meeting engine that sets up an exchange over theInternet in response to a caller's ID being associated with a caller forwhich a net meeting is appropriate.

A basic implementation of the aforementioned complete cordless telephonesystem described above, as observed in FIG. 5, is to implement: 1) thebasic cordless telephone function from within the “non main CPU/OS basedlower power” state 505; 2) the answering machine function from withinthe “main CPU/OS based low power” state 504; and, 3) the Net Meetingengine from within the “normal on” state 501. By implementing the basiccordless telephone function within the “non main CPU/OS based lowerpower” state 505, the computing system can easily convert itself, asdictated by its usage, back and forth between “just” a basic cordlesstelephone function and a full fledged computing system. Referring toFIGS. 4 a through 4 c as the underlying computing system, note that: 1)the Net Meeting engine is implemented with the complete computing systemof FIG. 4 a; 2) the answering machine is implemented with the lowerpower main CPU based system of FIG. 4 b; and, 3) the basic cordlesstelephone function is implemented with I/O unit 408 ₁.

Note that the functional implementations described just above areconsistent with their corresponding functional/processing capacity andpower consumption requirements. That is, a basic cordless telephonefunction can easily be constructed from a few simple components andtherefore: 1) can be easily integrated onto a single I/O unit (such asI/O unit 408 ₁); and, 2) will consume small amounts of power (relativeto an entire computing system). As such, a basic cordless telephone isan ideal function to be designed into I/O unit 408 ₁ as one of thecomputing system's “non main CPU/OS based lower power” state 505functions.

By contrast, an answering machine is a more complicated function thatrequires storage resources for both: 1) the recorded message to beplayed for a caller whose call has not been answered; and, 2) thecaller's recorded message (if any). As such, although an answeringmachine can be integrated onto an I/O unit, it is probably moreeconomical to use the storage resources of the computing system's mainmemory 404 for storing the recorded messages. Moreover, the main CPU 401and main OS can be used to execute application software that manages thehandling of recorded message playback (to both the caller whose call isnot being answered and the computing system user who desires to hear acaller's message).

Note also that an answering machine often records a message when theuser is not available to answer a call. As such, in most circumstancesit is not an inconvenience if the display 406 and graphics controller405 are not powered on (e.g., if the user is not at home to answer aphone call, the user is also not able to interface to the computingsystem through the display 406). Moreover, given that the main CPU 401and main OS can be used to assist the operation of the answering machineas described just above, note that the answering machine tasks are by nomeans “high performance” tasks for a typical computing system CPU 401.As a consequence, these tasks can be easily implemented if the main CPU401 is configured to have a reduced performance/power consumption state(e.g., by being forced to use lower internal voltages and/or lower clockfrequencies).

Taking all of the aforementioned characteristics of an answering machinetogether, note that the answering machine function is well suited forthe “main CPU/OS based low power” state 504. That is, referring to FIG.4 b, the display 406 and graphics controller 405 are inactive (so as toconserve power); and, the main CPU and OS can be used in a reducedperformance/power consumption capacity to handle the message playbackand message reporting functions. As a consequence, FIG. 5 indicates thatthe answering machine portion of the complete telephone system isimplemented with the “main CPU/OS based low power” state 504. Thus,reviewing the discussion of FIG. 5 so far, the computing system'simplementation of the telephone system are deliberately aligned with thecomputing system's operational states. That is, the lower power/lowerperformance basic cordless telephone function is designed into the “nonmain CPU/OS lower power” state 505; and, the more sophisticatedanswering machine function is designed into the “main CPU/OS low power”state 504.

Lastly, the Net Meeting function of the complete cordless telephonesystem of FIG. 5 is designed to be used while the computing system iswithin the “normal on” state 501. Here, software responsible forhandling a transaction over the Internet may involve higher performancetasks (e.g., Layer 4 flow control, IP layer header processing, etc.).Moreover, the Internet connection may be established over anothernetworking interface (e.g., a wireless interface) besides the POTSinterface associated with the cordless telephone. As such, the Internettransaction may involve the use of an I/O unit other than the I/O unitin which the basic cordless telephone function is integrated (e.g., I/Ounit 408 ₂ if I/O unit 408 ₂ provides a wireless interface). Thus, theNet Meeting function of the complete cordless telephone system is wellsuited for the computing system while it is within the “normal on” state(because the Internet communication capability of the normal computingsystem can largely be re-used for the Net Meeting communication functionof the cordless telephone system).

Because the computing system can transition across the various states inthe state diagram of FIG. 5, the complete cordless telephone systemdescribed above corresponds to a computing system that can swing backand forth between a “high power” computing system and a “lower power”basic cordless telephone based upon its usage. For example, as just oneexample, if a user is using the computing system for a traditionalcomputing system use (e.g., writing a document and/or writing adocument) the computing system will be in the “normal on” state 501. Ifthe user then subsequently suspends this activity so as to temporarilyabandon the computing system (e.g., by doing “something else” that isnot computer related), the computing system may automatically drop downto its lowest power active state 505 (the “non main CPU/OS based lowerpower state”) so as to behave and consume power as a basic cordlesstelephone system does. Note that in many cases a user may abandon acomputing system for hours at a time—thus, dropping the computing systemdown automatically into the lower power state(s) causes the computingsystem to regulate its own power consumption as a function of the mannerin which it is being used.

The computing system can also therefore be viewed as a hybrid between atraditional “high power” computing system and a low end appliance (inthis case, a basic cordless telephone). When the user uses the systemfor traditional computing purposes (e.g., document writing, web surfing,etc.), the system behaves as a traditional computing system; and, whenthe user is not using the system as a traditional computing system, thesystem degrades (in terms of functionality and power consumption) into abasic appliance (in this case, a basic cordless telephone function). Asthe state diagram observed in FIG. 5 indicates that the computing systemis capable of transferring back and forth between the various usefulstates 501, 504, 505; likewise, the computing system is capable oftransferring back and forth between a traditional computing system and abasic appliance.

Moreover, continuing with the example provided just above, if the user,after temporarily abandoning the computer, receives a telephone call andcannot answer the telephone call; then, the computing system can triggera state transition from the lowest power operable state 505 to theintermediate power operable state 504 so as to convert itself from abasic cordless telephone (as represented by state 505) into a basiccordless telephone having an answering machine (as represented by state504). In this case, note that the system is able to tweak its functionalabilities and corresponding power consumption in light of the overalluses that present themselves to the system.

Continuing with this same example, after recording the caller's message(e.g., by storing it to system memory 404), the software associated withthe “main CPU/OS based low power” state 504 may be written so as to dropthe system back into the lower power state 505 (absent the return of theuser for traditional computing system uses) so as to convert thecomputing system back into a basic cordless telephone. Thus, in light ofthese state transitions, note that the computing system is not only ableto tweak its functional capabilities and corresponding power consumptionbetween a traditional computing system (state 501) and basic appliance(the basic cordless telephone of state 505); but, is also able to tweakits functional capabilities and corresponding power consumption to thatof an “intermediate” appliance (the answering machine of state 504) aswell. Moreover, the above described conversions between the variousfunctional capabilities can be automatically triggered in light ofwhatever uses present themselves to the computing system over time.

An example of a complete cordless telephone system that shows a sequenceof events sufficient to cause the establishment of a net meeting isprovided in more detail below with respect to FIG. 11.

State Transition Methodology and Supporting Hardware

Given that the above example describes a working system that is able totransition itself between various useful states 501, 504, 505 (eachhaving their own degree of functional ability and power consumption),the manner in which these state transitions are implemented are of someimport. FIGS. 6 a,b through 8 a,b are directed to these state transitionaspects. In particular, FIGS. 6 a and 6 b provide methodologies forstate transition between the high power “normal on” state 301 and the“main CPU/OS based low power state” 304 of FIG. 3. FIGS. 8 a and 8 bprovide methodologies for state transition between the “main CPU/OSbased low power” state 304 and the “non main CPU/OS based lower power”state 305. FIG. 7 provides an embodiment of a circuit design that can beused to assist the state transition process.

FIG. 6 a shows an embodiment of a methodology that may be executed by acomputing system to transition from the high power “normal on” state 301to the “main CPU/OS based low power” state 304. According to themethodology of FIG. 6 a, the system is initially “executing” within the“normal on” high power state 601. In this state, the system can be usedfor traditional computing purposes. At some instant, an event isdetected 602 that triggers the transition process from the “normal on”state to the “main CPU/OS based low power” state. The event may varyfrom embodiment to embodiment and application to application.

For example, as just a few possible instances, the computing system mayrecognize that no stimulus has been provided by a user over an extendedperiod of time (e.g., the user has not used a mouse or typed on akeyboard for an extended period of time); or, the computing system mayrecognize that the user has closed the lid of the computing system (ifthe computing system is a handheld device such as a laptop/notebookcomputer); or, has powered off the screen/display (if the computingsystem is a typical “desktop” system). Note that whether the eventshould cause the system to enter the “main CPU/OS low power” state or aprior art sleep state 303 may be determined in light of variousconditions that may vary from embodiment to embodiment and applicationto application. As just one example, if a lower power operational stateis recognized as being “active” by setting a flag in software (e.g., ifthe basic cordless telephone system is recognized as being active), thesystem automatically transfers to a lower power operational state 304,305 rather than a prior art sleep state 303.

In response to the detected event 602, the OS marks itself 603 as beingwithin the “main CPU/OS low power” state. Here, recall again that the“main CPU/OS” component of this low power but operational state meansthat the main CPU is still operational and the main OS is stilloperational so that one or more application software programs can beexecuted on the main CPU and OS. As such, the OS marks itself 603 sothat it can formally recognize that it is operating within a lower powerstate. Appropriate software drivers may similarly mark themselves. The“main CPU/OS based low power” state 304 is then setup or established604. In this case, recall that state 304 may be implemented by: 1)stripping the authority of various components (e.g., the graphicscontroller and display) to regulate their own power consumption; and/or2) forcing the CPU to remain within a lower performance/lower powerconsumption mode; and/or 3) parking certain application softwareprograms or tasks; and/or 4) reducing the number of active main CPUswithin a multiple main CPU system; and/or, 5) removing or lowering powerto various components. Any software that is deactivated for the “mainCPU/OS low power” state may have its context saved so that it can recallits operating environment upon return to the “normal on” state. Once the“main CPU low power state” has been set up, the system executes 605 inthat state.

The transition of the system from the “main CPU/OS based low power”state to the “normal on” state, an embodiment of which is observed inFIG. 6 b, can be implemented as largely the reverse of the “normal on”state to “main CPU/OS based low power” state transition. That is,referring to FIG. 6 b, while executing 606 within the “main CPU/OS basedlow power” state, an event is detected 607 that triggers a statetransition toward the “normal on” state. Again, the precise nature ofthe triggering event 607 may vary from embodiment to embodiment andapplication to application. In the case of an answering machine, asdescribed above with respect to FIG. 5, the triggering event 607 may bethe recognition that a Net Meeting needs to be established for apresently received call.

In response to the triggering event 607, the OS and applicable devicedrivers mark themselves 608 as being within the “normal on” state. The“normal on” state is then established/setup 609 (e.g., by grantingvarious components to regulate their own power consumption, allowing themain CPU to operate in a higher performance/power consumption mode,re-activating “parked” application software programs and re-storingtheir context, re supplying various components with their proper supplypower). Once the “normal on” state is established, the system executes610 in the “normal on” state.

Because the main CPU/OS is powered/kept awake during the “main CPU/OSbased low power” state, the main CPU and main OS are not put to sleepduring a state transition process between the “normal on” state and the“main CPU/OS based lower power state”. By contrast, the “non mainCPU/OS” component of the “non main CPU/OS based lower power” stateindicates that main CPU/OS are put into an inactive state. As aconsequence, transitioning to the “non main CPU/OS based lower power”involves putting the main CPU/OS into a sleep state. Generally, when themain CPU/OS “awakes” after being put to sleep, the initial phases of the“wake-up” process are similar to those processes that are executed whenthe entire computing system is first powered on as a whole or when thecomputing system comes out of a RESET condition. That is, basic BIOSsoftware has to be loaded and executed along with the OS itself.

A principle difference, however, between a basic power up or RESETresponse and a return from a sleep state is that, when returning from asleep state, the initial software loading process recognizes that thesystem is returning from a sleep state. This recognition, in turn,causes the reloading of the previously stored context. By contrast, wheninitializing from a basic power up or RESET, no such recognition orcontext exists. Here, one or more specific bits that are stored inspecific looked for locations are used during the wake up process sothat the system can determine whether it is initializing from a basicpower up/RESET or a from a sleep state (and in various cases what typeof sleep state the system is being awoken from). If one or more bitsindicate that the system is returning from a sleep state the savedcontext is restored so that system can return to its originalenvironment.

The existence of these looked for bits indicate that some limited amountof hardware associated with the CPU and/or memory controller and/or I/Ocontroller function remains powered on during the time period in whichthe main CPU/OS is sleeping. An embodiment of this limited hardware isobserved in FIG. 7. The specific circuit design of FIG. 7 not onlyprovides for recovery from a sleep state that was initiated by entryinto a “non main CPU/OS based low power state”; but also, is compatiblewith recovery from prior art ACPI compliant sleep state(s). As such,referring to FIGS. 3 and 7, the circuit design of FIG. 7 can be used byan ACPI compatible system to handle both: 1) the transition fromtraditional sleep state(s) 303; and, 2) the transition from the “nonmain CPU/OS based lower power” state 305.

In various embodiments the circuit used for recovery from a sleep state(such as the circuit of FIG. 7) is integrated with the memory controllerand/or I/O controller functions. In a further embodiment, the memorycontroller function is implemented with a first semiconductor chip andthe I/O controller function is implemented with a second semiconductorchip. In this case the circuit used for recovery from a sleep state(such as the circuit of FIG. 7), may be integrated onto either thememory controller semiconductor chip or the I/O controller semiconductorchip.

Referring now to FIG. 7, a “looked for” bit that indicates to a wakingsystem whether or not the system is waking from a sleep state or from abasic power/RESET state corresponds to bit 702 (“WAK_STS”). Theoperation that determines the state of the “WAK_STS” bit 702 will bedescribed in more detail below. The “SLP_EN” and “SLP_TYP” bits 712, 713are written to when the system as a whole is entering a traditional “nonoperational” sleep state (e.g., state(s) 303 of FIG. 3). Here, the“SLP_EN” bit 712 indicates that the system is entering a traditional nonoperational sleep mode and the “SLP_TYP” bits 713 indicate what specifictype of traditional non operational sleep state is being entered (e.g.,S0 through S4 in an ACPI based system) noting that the particularSLP_TYP embodiment of FIG. 7 uses three bits.

When the system is entering a traditional non operational sleep state,both the “SLP_EN” and “SLP_TYP” bits 712, 713 are used by the wake/upsleep logic 701 to establish the appropriate power supply voltage schemewithin the computing system. That is, each type of traditional sleepstate mode may have its own unique power supply voltage scheme (e.g.,some components may have supply removed, some components may have powersupply voltage reduced, etc.). Output 709 is used to implement theproper power supply scheme for the indicated traditional sleep mode.Note that if a particular sleep mode scheme logically disables one ormore components rather than tweaking their power supply voltage (e.g.,by shutting down an input clock, activating a disable bit, etc.), wakeup/sleep logic 701 and output 709 may be used for disablement purposesas well.

The “NMC/O_EN” bit 710 is written to when the system is transitioningfrom the “main CPU/OS based low power” state 304 to the “non main CPU/OSbased lower power” state 305. Here, because the “non main CPU/OS basedlower power” state may have its own unique power supply voltage scheme(e.g., as to what specific components have their supply power removed,reduced, etc.), in one embodiment, the wake up/sleep logic 701 has aspecial “NMC/O_EN” input bit 710 to indicate that the power supplyscheme specific to the “non main CPU/based lower power state” is to beengaged.

In an alternate embodiment the notion of “sleep”, even within the “nonCPU/OS based lower power” state, is marked by the “SLP_EN” and “SLP_TYP”bits 712, 713 (e.g., by using a unique/heretofore unused combination ofSLP_TYP bits to signify the “non main CPU/OS based” state). Here, the“NMC/O_EN” bit can be used as additional information that, when set,informs the wake up/sleep logic 701 that “non main CPU/OS based lowerpower” state is being transitioned to. Regardless, the output 709 isused to establish the proper power scheme. Again, note that if the “nonmain CPU/OS based lower power” state 305 logically disables one or morecomponents rather than tweaking their power supply voltage (e.g., byshutting down an input clock, activating a disable bit, etc.), wakeup/sleep logic 701 and output 709 may be used for disablement purposesas well.

The input bits 704, 714 to the multiple input OR gate 703 are wake eventbits. That is, upon the arrival of an event sufficient to cause the mainCPU/OS to be awoken from a traditional sleep state or the “non mainCPU/OS based lower power” state, at least one of these input bits 710,714 is activated. This causes net 708 to become active; which, in turn,causes the WAK_STS bit 702 to become active. In response to the WAK_STSbit 702 being active, the main CPU/OS recognizes that it is being awokenfrom a sleep state; and, then, may look to bits 704, 714 to furtherrecognize why the system was awoken. Moreover, depending onimplementation, the main CPU/OS can recognize that it is being awokenfrom the “non main CPU/OS based lower power” state by reading the statusof the NMC/O_EN bit 710 or the status of the NMC/O_STS bit 714.

Because the NMC/O_EN bit 710 is set active to enter the system into the“non main CPU/OS based lower power” state, in one embodiment, bit 710can be read during wake up in order to recognize that the system iswaking up from the “non main CPU/OS based lower power” state. Note that,in this case, bit 710 is a read/write bit in the sense that it can beboth written to (for entry into the “non main CPU/OS based lower power”state) and read from (for transition from the “non main CPU/OS basedlower power” state). In this particular case, the NMC/O_STS bit 714 isused simply to notify the circuitry of FIG. 7 that the system is beingremoved from the “non CPU/OS based lower power” state (i.e., a wake upevent has occurred).

In an alternate embodiment where the SLP_TYP bits 713 are used toindicate that the system is entering the “non main CPU/OS based lowerpower” state (e.g., through a unique/heretofore unused combination ofSLP_TYP bit settings), these same SLP_TYP bits are read from in order torecognize that the system is awaking from the “non main CPU/OS basedlower power” state. In another alternate embodiment, the system isconfigured to look to the NMC/O_STS bit 714 to recognize whether or notthe system is waking from the “non CPU/OS based lower power” state(i.e., if bit 714 is active upon wake-up; then, the system is waking upfrom the “non main CPU/OS based lower power” state). Bits 704 are “priorart” ACPI bits that correspond to traditional wake events (e.g.,vis-á-vis the LID_STS bit, the opening of a laptop/notebook computer'spreviously closed lid).

FIGS. 8 a and 8 b show, respectively, methodologies sufficient fortransitioning the computing system from the “main CPU/OS based low powerstate” 304 to the “non main CPU/OS based lower power” state 305 (FIG. 8a); and, from the “non main CPU/OS based lower power” state 305 to the“main CPU/OS based low power state” 304 (FIG. 8 b). Referring to FIG. 8a, the system is initially executing within the “main CPU/OS based lowpower” state 801. At some point, an event is detected 802 sufficient totrigger the system into the “non main CPU based lower power” state 305(e.g., the answering machine function 504 of FIG. 5 has completed itsrecording of an unanswered caller's call and the user has not returnedto the computing system).

As a consequence, the main CPU and OS are put to sleep 805. Thisinvolves: 1) preparing the OS and drivers for the transaction and thestoring of context 803; and, 2) recording that the main CPU/OS is beingput to sleep because it is entering the “non main CPU/OS based lowerpower” state (e.g., by setting the NMC/O_EN bit 710 of FIG. 7 and/or theSLP_EN and SLP_TYP bits 712, 713) and setting up 804 the “non mainCPU/OS based lower power” power consumption state (e.g., by poweringdown the power planes for the CPU, memory controller, system memory,etc.; e.g., as provided by wake up/sleep logic 701). After this has beendone, the system executes 806 from the “non main CPU/OS based lowerpower” state.

FIG. 8 b provides a more generic wake up sequence that the computingsystem may follow as it awakes from either a traditional sleep state 303or from the “non main CPU/OS based lower power” state 305. According tothe process of FIG. 8 b, a wake event 807 triggers the main CPU to comeout of a sleep state and the BIOS software is loaded 808. In the case ofa transition from a traditional sleep state the wake event 807 may be anindication that the user has returned to use the system (e.g., bylifting the lid of a closed notebook/laptop vis-á-vis the LID_STS inputof FIG. 7). In the case of a transition from the “non main CPU/OS basedlower power” state, the wake event 807 may be caused by a need to use afunction that is not operable within the lower power state (e.g., ananswering machine in light of an unanswered call).

In response to the BIOS being loaded so as to initialize appropriatehardware, control of the system is handed off to the main OS whichdetermines 809 whether or not the wake up event 807 corresponds to atransition from a traditional sleep state 303 or from the “non CPU/OSbased lower power” state 305. Here, depending on implementation, themain OS can refer to bits 712, 710 and/or 714 of FIG. 7 to make thisdetermination 809. If the system is transitioning from a traditionalsleep state 303, a prior art wake up sequence may be followed 810. Ifthe main OS determines that the system is transitioning from the “nonmain CPU/OS based low power” state, the main OS will attempt tounderstand 810 why the non main CPU/OS based subsystem generated thetrigger event.

Here, if the non main CPU/OS lower power subsystem includes a processorthat executes software (as explained in more detail below with respectto FIG. 9), the main CPU/OS can send a message to the non main CPU/OSlower power subsystem to determine why the trigger event 807 wasgenerated. If the non main CPU/OS subsystem does not execute software,the main OS can look into, for example, additional hardware bits thatwere set by the non main CPU/OS to inform the main OS as to the natureof the trigger event 807.

Note that, bit 710 of FIG. 7 can be deactivated to cause wake up/sleeplogic 701 of FIG. 7 to properly power up the hardware into a “normal on”state (e.g., as observed in FIG. 4 a) if the transition is from atraditional sleep state 303. Likewise, depending on implementation, bit710 and/or bit 712 can be deactivated to cause wake up/sleep logic 701to properly power up the hardware into a “main CPU/OS based low power”state (e.g., as observed in FIG. 4 b) if the transition is from the “nonmain CPU/OS based low power” state 305.

Non Main CPU/OS Based Lower Power State Hardware and Software Design

FIGS. 9 a and 9 b are presently used to support a more detaileddiscussion of possible hardware and software designs for the “non mainCPU/OS based lower power” state. Here, the present discussion can beviewed as a more detailed elaboration of the discussion that wasoriginally presented with respect to FIG. 4 c. Referring briefly back toFIG. 4 c, recall that a simplistic version of the hardware used toimplement the “non main CPU/OS based lower power” state was provided;where, more specifically, a single I/O unit 408 ₁ was activated toimplement the non main CPU/OS state 305.

By contrast more elaborate non main CPU/OS state 305 hardwareimplementations are presently envisioned that can be viewed as lowerpower/lower performance computing systems having identifiable softwareand I/O. FIG. 9 a shows an example. In the depiction of FIG. 9 a, acomputing system is shown having a main CPU/OS based system (whichinclude main CPU 901, cache 902, system memory 904, graphics controller905, main display 906, etc.). Many major components of the main CPU/OSbased system are deactivated while in the “non main CPU/OS based lowerpower” state. Similar to the scheme of FIGS. 4 a through 4 c, thecomponents which are deactivated during the “non main CPU/OS based lowerpower” state are drawn as shaded regions in FIG. 9 a.

Hence, according to the embodiment of FIG. 9 a, the computing systemused to implement the “non main CPU/OS based lower power” state includesits own distinctive: 1) controller 917 (which may be implemented by alower performance/lower power processor, microcontroller, logic statemachine, etc. as compared to the main CPU); 2) primary memory 918 (whichmay be implemented with lower speed random access memory (RAM) and/orless dense RAM as compared to the main system memory 904); 3) userinterface 925 (which may include a display 919, keyboard/buttons 920 andLED 924); 4) system bus 923; 5) I/O unit 922 (which may be implemented,as just one example, with storage resources such as a FLASH based memoryor polymer based memory); and, 5) FLASH memory 921.

Apart from the distinctive features highlighted just above, note thatthe computing system used to implement the “non main CPU/OS based lowerpower” state may also share various I/O units with the main CPU/OScomputing system. In the embodiment of FIG. 9 a, the shared I/O unitsinclude: 1) a MODEM unit 909; 2) a Wireless Local Area Network (WLAN)unit 911; and, 3) a Wireless Wide Area Network (WWAN) unit 913. Here,these “shared” I/O units 909, 911, 913 are active during the “non mainCPU/OS based lower power” state. Other shared I/O interface units arepossible as well (e.g., Bluetooth). In various embodiment, “shared” I/Ounits operate within the pair of computing systems (main CPU/OS and nonmain CPU/OS) by taking commands from the main CPU/OS system when not inthe “non main CPU/OS based lower power” state; and, by taking commandsfrom the non main CPU/OS system when in the “non main CPU/OS based lowerpower” state). It is also possible that a shared I/O unit may be pluggedinto the main system bus 907 (e.g., I/O unit 908 _(N) as represented bycommunication interface 926).

In one embodiment, interfaces 910, 912, 914 and 916 (which are inactiveduring the “non main CPU/OS based lower power” state) respectivelycorrespond to: 1) for interface 910, a serial port interface (in whichcase MODEM 909 may further correspond to a V.90 MODEM 909); 2) forinterface 912, a USB interface for an IEEE 802.11 based networkinterface card; 3) for interface 914, a serial interface for a GeneralPacket Radio Services (GPRS) wireless modem; for 4) for interface 916,an ATA-100 interface for an IDE Hard disk Drive (HDD). In furtherembodiments, a Universal Serial Bus (USB) interface that emanates fromthe I/O controller portion of the memory and I/O control function 903(not shown in FIG. 9 a for simplicity) is deactivated within the “nonmain CPU/OS based lower power” state and includes having a Bluetooth I/Ounit. Here, the Bluetooth interface unit may also be shared so as to beactive during the “non main CPU/OS based lower power” state.

In another embodiment the system bus 923 can be the same system bus 907.In this case the main CPU 901 can access devices 908 ₁ to 908 _(N) inaddition to the Controller 917 while in the “normal on” State 301.However the Controller 917 can then access devices 908 ₁ to 908 _(N)through the system bus 923/907 (which in this embodiment is the samebus, but not shown in FIG. 9 a for clarity) when the system is in the“non main CPU/OS lower power” state 304. Note that in this embodiment,devices 908 ₁ to 908 _(N) would remain active (not shaded) in the “nonmain CPU/OS lower power” state 304 in order for the Controller 917 toaccess them.

Note that the non main CPU/OS system may include its own distinctiveuser interface 925. The embodiment of FIG. 9 a indicates that thedistinctive user interface includes an LED 924 (whose status iscontrolled by controller 917), a display 919, and keyboard/button(s)920. The mechanical positioning/layout of the user interface 925 may addto its distinctiveness with respect to the “non main CPU/OS based lowerpower” state. In particular in a mobile computing application (e.g.,laptop/notebook computer) the user interface 925 may be positioned/laidout so that the user can view the display 919 and LED 924; and/or usethe keyboard/button(s) 920 when the lid of the main display 906 isclosed so as to cover the main keyboard FIG. 9 b shows a pair oflaptop/notebook computing systems each having a user interface that canbe accessed when the “lid” of the computing system is closed.

Examples of data which could be accessed on this closed lid userinterface are calendar, contact and to do information; commonly referredto as Personal Information Management (PIM) data; however it is notlimited to this type of data and can include any information which mightbe important for an end user that uses a notebook computer in a “closedlid” state (e.g. current sales data for a traveling salesperson).Additionally the overall computing system may allow for the control offunctions within the notebook through a closed lid user interface. Anexample of this could be the playing of MP3 music files stored on thecomputer through a wireless headset. In this case the user could controlthe playing of music (song selection, volume, and other attributes)through the closed lid user interface.

Referring back to FIG. 9 a, note that the non main CPU/OS computingsystem may be implemented with a controller 917 that may be, in turn,implemented as a microprocessor or micro-controller. As a consequence,embodiments are envisioned where the non main CPU/OS computing systemexecutes its own software routines. FIG. 10 shows a diagram thatdemonstrates how the software of the non main CPU/OS computing system(right hand side of FIG. 10) might cooperate with software that isexecuted by the main CPU and OS. That is, recalling that the non mainCPU/OS computing system may remain powered on and active during both the“active on” state and the “main CPU/OS based lower power” state, it ispossible that a “dual system” may be implemented in which software fromboth systems (main CPU/OS and non main CPU/OS) operate with one anotheras a cooperative whole during either the “active on” state or the “mainCPU/OS based lower power” state. FIG. 10 attempts to demonstrate thisrelationship.

FIG. 10 can be viewed as (although should be not be construed as beingsolely limited to) an embodiment of a system which utilizes a closed liduser interface (such as those shown in FIG. 9 b) to access relevant enduser data, or to control useful end user functions while thelaptop/notebook computer's lid is closed. FIG. 10 shows how functions ofoperation are distributed between the different system states describedin FIG. 3: “normal on” state 301, “main CPU/OS based” state 304 and the“non main CPU/OS based” state 305.

The right hand side of FIG. 10 shows software components of the non mainCPU/OS computing system. These include non main operating system (i.e.,non main OS) components such as: 1) an application programmer'sinterface (API) 1001; 2) a management function 1002 (which can includeboth event management and function management routines); 3) a datastorage management function 1003 (to control the non main CPU/OScomputing system's use of its distinctive data storage resources (suchas FLASH or polymer memory 922 of FIG. 9 a)); and, 4) a user interfacemanagement function 1004 (to control the non main CPU/OS computingsystem's use of its distinctive user interface (such as user interface925 of FIG. 9 a).

Application software 1005, 1006 may also reside on the non main CPU/OScomputing system. Application software can typically broken down intotwo types: 1) data storage 1005 (which is directed to the use/managementof stored data); and, 2) functional 1006 (which are directed to usefulfunctions to be performed by the underlying controller 917).

As with typically software environments, the non main CPU/OS computingsystem applications 1005, 1006 interface with the non main CPU/OScomputing system operating system through an API 1001.

When in the “non main CPU/OS based lower power” state, the non mainCPU/OS computing system (including software components 1001 through1006) operates independently. Also, because the main CPU/OS is inactiveduring the “non main CPU/OS based lower power” state, softwarecomponents 1007 through 1012 that run on the main CPU/OS are likewiseinactive. However, when the overall system is within the “normal active”state or the “main CPU/OS based low power state” various softwarecomponents that run on the main CPU/OS are active; and, moreover,because the non main CPU/OS computing system remains active duringeither of these states, the software from both systems may work togetheras a cooperative whole.

For example, by being cognizant of certain resources that are under thecontrol of the non main CPU/OS computing system, the main CPU/OS sidesoftware may be configured to “use” these resources. For example,software routines on the main CPU/OS computing system may be configuredto utilize data storage or memory resources that are distinctive to thenon main CPU/OS computing system (e.g., such as units 918, 921 and 922of FIG. 9 a). As another example, software routines on the main CPU/OScomputing system may be configured to affect the status of variousresources associated with a user interface that is distinctive to thenon main CPU/OS computing system. For example, as explained in moredetailed below, a cordless telephone answering machine that isimplemented within the “main CPU/OS based low power” state (as describedwith respect to FIG. 5) may desire to repeatedly flash “on and off” anLED (such as LED 924 of FIG. 9 a) that is associated with the non mainCPU/OS based user interface (e.g., to inform a user that a message hasbeen recorded for the user to listen to). A description of such anembodiment will be explained in more detail below with respect to FIG.11.

In order for the main CPU/OS software 1007 through 1012 to “work with”the non main CPU/OS software 1001 through 1006, such software may sendmessages to the non main CPU/OS controller 917 to request certainactions or can pass data objects for storage 1003. The applicationsoftware may again be broken down into data applications 1009, 1010 andfunctional applications 1013, 1011. However, some of these applications1009, 1013 may be pre-written with an understanding that resources on anon-main CPU/OS computing system are available; whereas, other (e.g.,older “legacy”) software applications 1010, 1011 may have been writtenwithout any recognition or cognizance that such resources exist. Forthose software applications of the later type, “proxy” software 1007,1008 that acts as a “glue layer” may be used to force or otherwise causethe legacy applications to be able to operate cooperatively with the nonmain CPU/OS system resources. Functional blocks 1002, 1003 and 1004allow the User to interact with the User Interface 925 to display PIMand other information or to control some functions like playing MP3files. The manager 1002 accepts data objects which are then stored inthe storage block 1003. These data objects represent data to bedisplayed on the user interface (PIM or other data) and originate indata applications 1005, 1010 or 1009. The applications 1010 and 1007operate in the “normal on” state 301 and are responsible for providingdata objects to be stored in storage 1003 through the API 1001 via theManager 1002. Examples of Legacy Data Applications 1010 are presentversions of Outlook™ and Lotus Notes™ which contain PIM data but have noknowledge of how to create data objects that the User Interface 1004 canunderstand or how to move these objects to the Storage 1003. The ProxyApplication 1007 is responsible for this function, and essentially pullsthe appropriate date from the Legacy application, formats it into thecorrect data object, and then passes these data objects to the Manager1002 via the API 1001 to be stored by the Storage 1003. In the futurethese types of applications will build in these exporting functions andare represented by the Data Application 1009.

Functions that will operate in the “main CPU/OS based” state 304 and arecontrolled by this user interface 925/1004 include applications 1011,1008 and 1013. Again Legacy Function represents something that isunaware of the non-main CPU/OS functions, and therefore require a mainCPU/OS Proxy driver to interface with these functions. An example of onesuch application is a legacy media player which can play music files. Inthis case a proxy application 1008 can be written to allow the UserInterface 1004 to control this application while in the main CPU/OSbased state 304. This application would allow the user to controlplaying of media songs stored on the subsystems available in the mainCPU/OS based state 304 and then output through some audio interface. Inthe future these types of applications will build in these proxyfunctions and are represented by the Function Application 1013.

Functions that operate in the non main CPU/OS based state 305 reside onthe right side of the diagram. The User Interface 1004 is responsiblefor reacting to user button presses (Keyboard/Buttons 920) and thendisplaying the data objects on the Display 919. Embedded within the dataobjects are navigation commands that tell the User Interface whichobjects to display next based on which button is pressed. Additionallythe Manager will allow the user to control MP3 playback through an MP3non main CPU/OS based lower power state Function Apps 1006; which isresponsible for getting the MP3 file from storage 1003, decoding thefile and sending the output through a Bluetooth interface to a wirelessheadset.

An example of a data storage application 1005 is an application thatconnects back to an enterprise server to retrieve new PIM data objectswhich can then be put in Storage 1003 for access by the user through theUser Interface 1004. In this case the application 1005 would accessthese new data objects through a wireless communication device operatingin the non main CPU/OS based state 305 (such as the WLAN 911 or WWAN913)

FIG. 11 shows another embodiment of the state transitions that may ariseover the course of operation of complete cordless telephone system asdescribed with respect to FIG. 5. However, the example of FIG. 11 isslightly more elaborate than the discussion of FIG. 5 in that both anLED is flashed (to indicate to a user that a message from an unansweredphone call has been recorded and is waiting for the user) and a netmeeting is established. According to the approach of FIG. 11, over atime period T1, the system is originally within the “non main CPU/OSbased lower power” state 505, 1101 where no activity/use of the computerarises other than that of a basic cordless telephone.

At point in time T2 a call is made into the cordless telephone and noone answers. As a consequence a transition into the “main CPU/OS basedlow power state” 504, 1102 is caused to realize the answering machinefunction. Over a time period T3, the answering machine function answersthe phone, plays a message to the caller, records the callers messageand causes an LED to repeatedly flash on the user interface that isdistinctive to the non main CPU/OS computing system (e.g., LED 924 ofFIG. 9 a). Note that the later function of causing the LED to flashcorresponds to a cooperative workflow between answering machine softwarethat resides on the main CPU/OS; and LED software/hardware that isdistinctive to the non main CPU/OS computing system.

Upon completion of the above functions, at time T4, the overallcomputing system transitions back into the “non main CPU/OS based lowerpower” state 505, 1103. At time T5, with the LED continuing to flash(i.e., it does not stop flashing until the user listens to the recordedmessage), the phone again rings. However, this time, the user answersthe phone and recognizes that the present call is in regard to a netmeeting that needs to be established. The user presses a “net meeting”button found on the non main CPU/OS computing system user interface(e.g., associated with keyboards/buttons 920 of FIG. 9 a).

The pressing of the “net meeting” button causes a first transition intothe “main CPU/OS based lower power” state 505, 1104 and a secondtransition into the “normal on” state 501, 1105. In the “normal on”state, the caller ID of the incoming phone call and the resources of themain CPU/OS are utilized to establish a net meeting and perform workthere under (e.g., by modifying a common document with anotherindividual over the internet). The LED continues to flash under thecontrol of the non main CPU/OS computing system because the user hasstill not listened to the recorded message.

It is also to be understood that because embodiments of the presentteachings may be implemented as one or more software programs,embodiments of the present teachings may be implemented or realized uponor within a machine readable medium. A machine readable medium includesany mechanism for storing or transmitting information in a form readableby a machine (e.g., a computer). For example, a machine readable mediumincludes read only memory (ROM); random access memory (RAM); magneticdisk storage media; optical storage media; flash memory devices;electrical, optical, acoustical or other form of propagated signals(e.g., carrier waves, infrared signals, digital signals, etc.); etc.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will, however,be evident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the invention asset forth in the appended claims. The specification and drawings are,accordingly, to be regarded in an illustrative rather than a restrictivesense.

1. A machine readable medium having instructions for a computing system,said instructions when executed performing a method comprising: a)making the computing system to operate within a non main CPU/OS basedoperational state while a main system bus of the computing systemremains active, wherein an independent controller may operate functionaltasks while the computing system is within the non main CPU/OS basedoperational state, the controller being coupled to the main system bus;and b) maintaining active an I/O unit interface coupled to said mainsystem bus while said computing system operates within said non mainCPU/OS based operational state.
 2. The machine readable medium of claim1, in which the computing system comprises wake-up/sleep logic circuitrycoupled to power control circuitry to establish said main CPU/OS basedoperational state and said non main CPU/OS based operational state, saidI/O unit interface coupled downstream from said power control circuitry.3. The machine readable medium of claim 2 wherein said computing systemis a notebook or laptop computer.
 4. The machine readable medium ofclaim 1, in which the computing system comprises an LED that is coupledto said second CPU, said LED observable to a user of said computingsystem when the lid of said notebook or laptop computer is closed. 5.The machine readable medium of claim 4, in which the computing systemcomprises a display that is coupled to said controller, said displayobservable to a user of said computing system when the lid of saidnotebook or laptop computer is closed.
 6. The machine readable medium ofclaim 5, in which the computing system comprises a keyboard and/or oneor more buttons coupled to said controller, said keyboard and/or one ormore buttons observable to a user of said computing system when the lidof said notebook or laptop computer is closed.
 7. The machine readablemedium of claim 1, wherein said I/O unit is coupled to said controllerthrough a bus.
 8. The machine readable medium of claim 1, wherein saidcontroller is coupled to at least one of a FLASH memory and a polymermemory.
 9. The machine readable medium of claim 1, wherein said I/O unitis a wireless unit.
 10. An apparatus, comprising: a machine readablemedium having instructions that when executed, implement at least partof an operating system for a computer system to: (a) allow a first CPUto operate during a main CPU/OS based operational state; (b) cooperatewith a second CPU that can execute program code during a non main CPU/OSbased operational state, wherein, first power consumed by said first CPUduring said main CPU/OS based operational state is greater than secondpower consumed by said second CPU during said non main CPU/OS basedoperational state; c) facilitate the first CPU to provide data from thefirst CPU to the second CPU through a wireless unit coupled to both anI/O unit interface for the first CPU and said second CPU; and d) enablethe data to be written into a non volatile storage unit for the secondCPU so that the second CPU can use the data during the non main CPU/OSbased operating state when the first CPU is not active.
 11. Theapparatus of claim 10 comprising wake-up/sleep logic circuitry coupledto power control circuitry to establish said main CPU/OS basedoperational state and said non main CPU/OS based operational state, saidI/O unit interface coupled downstream from said power control circuitry.12. The apparatus of claim 10, wherein said computing system is anotebook or laptop computer.
 13. The apparatus of claim 12 furthercomprising an LED that is coupled to said second CPU, said LEDobservable to a user of said computing system when the lid of saidnotebook or laptop computer is closed.
 14. The apparatus of claim 13further comprising a display that is coupled to said second CPU, saiddisplay observable to a user of said computing system when the lid ofsaid notebook or laptop computer is closed.
 15. The apparatus of claim14 further comprising a keyboard and/or one or more buttons coupled tosaid second CPU, said keyboard and/or one or more buttons observable toa user of said computing system when the lid of said notebook or laptopcomputer is closed.
 16. The apparatus of claim 10 wherein said I/O unitis coupled to said second CPU through a bus.